Search results for "decay [Higgs particle]"
showing 10 items of 254 documents
On a class of singular measures satisfying a strong annular decay condition
2018
A metric measure space $(X,d,\mu)$ is said to satisfy the strong annular decay condition if there is a constant $C>0$ such that $$ \mu\big(B(x,R)\setminus B(x,r)\big)\leq C\, \frac{R-r}{R}\, \mu (B(x,R)) $$ for each $x\in X$ and all $0<r \leq R$. If $d_{\infty}$ is the distance induced by the $\infty$-norm in $\mathbb{R}^N$, we construct examples of singular measures $\mu$ on $\mathbb{R}^N$ such that $(\mathbb{R}^N, d_{\infty},\mu)$ satisfies the strong annular decay condition.
Direct observation of theBa114→Xe110→Te106→Sn102tripleα-decay chain using position and time correlations
2016
The triple $\ensuremath{\alpha}$-decay chain $^{114}\mathrm{Ba}\ensuremath{\rightarrow}^{110}\mathrm{Xe}\ensuremath{\rightarrow}^{106}\mathrm{Te}\ensuremath{\rightarrow}^{102}\mathrm{Sn}$ has been directly observed for the first time, following the $^{58}\mathrm{Ni}(^{58}\mathrm{Ni},2n)$ reaction. Implantation of $^{114}\mathrm{Ba}$ nuclei into a double-sided silicon-strip detector has allowed their $\ensuremath{\alpha}$ decays to be correlated in position and time with the $\ensuremath{\alpha}$ decays of the daughter $(^{110}\mathrm{Xe})$ and granddaughter $(^{106}\mathrm{Te})$ nuclei. In total, 17 events have been assigned to the $^{114}\mathrm{Ba}\ensuremath{\rightarrow}^{110}\mathrm{Xe}…
β-delayed fission andαdecay ofAt196
2016
A nuclear-decay spectroscopy study of the neutron-deficient isotope $^{196}\mathrm{At}$ is reported where an isotopically pure beam was produced using the selective Resonance Ionization Laser Ion Source and On-Line Isotope Mass Separator (CERN). The fine-structure $\ensuremath{\alpha}$ decay of $^{196}\mathrm{At}$ allowed the low-energy excited states in the daughter nucleus $^{192}\mathrm{Bi}$ to be investigated. A $\ensuremath{\beta}$-delayed fission study of $^{196}\mathrm{At}$ was also performed. A mixture of symmetric and asymmetric fission-fragment mass distributions of the daughter isotope $^{196}\mathrm{Po}$ (populated by $\ensuremath{\beta}$ decay of $^{196}\mathrm{At}$) was deduce…
Mass spectrometry of atomic ions produced by in-trap decay of short-lived nuclides
2005
The triple-trap mass spectrometer ISOLTRAP at ISOLDE/CERN has demonstrated the feasibility of mass spectrometry of in-trap-decay product ions. This novel technique gives access to radionuclides, which are not produced directly at ISOL-type radioactive ion beam facilities. As a proof of principle, the in-trap decay of $^{37}K^+$ has been investigated in a Penning trap filled with helium buffer gas. The half-life of the mother nuclide was confirmed and the recoiling $^{37}Ar^+$ daughter ion was contained within the trap. The ions of either the mother or the daughter nuclide were transferred to a precision Penning trap, where their mass was determined.
A measurement of the tau lifetime
1993
The tau lepton lifetime is measured using four different methods with the DELPHI detector. Three measurements using one prong decays are combined, accounting for correlations, resulting in tau(tau) = 298 +/- 7 (stat.) +/- 4 (syst.) fs while the decay length distribution of three prong decays gives tau(tau) = 298 +/- 13 (stat.) +/- 5 (syst.) fs. The combined result is tau(tau) = 298 +/- 7 fs. The ratio of the Fermi coupling constant from tau decay relative to that from muon decay is found to be 0.985 +/- 0.013, compatible with lepton universality.
Superallowed α Decay to Doubly Magic Sn100
2018
We report the first observation of the ^{108}Xe→^{104}Te→^{100}Sn α-decay chain. The α emitters, ^{108}Xe [E_{α}=4.4(2) MeV, T_{1/2}=58_{-23}^{+106} μs] and ^{104}Te [E_{α}=4.9(2) MeV, T_{1/2}<18 ns], decaying into doubly magic ^{100}Sn were produced using a fusion-evaporation reaction ^{54}Fe(^{58}Ni,4n)^{108}Xe, and identified with a recoil mass separator and an implantation-decay correlation technique. This is the first time α radioactivity has been observed to a heavy self-conjugate nucleus. A previous benchmark for study of this fundamental decay mode has been the decay of ^{212}Po into doubly magic ^{208}Pb. Enhanced proton-neutron interactions in the N=Z parent nuclei may result …
First β -decay scheme of Nb107 : New insight into the low-energy levels of Mo107
2019
Monoisotopic samples of $^{107}\mathrm{Nb}$ nuclei, produced in the proton-induced fission of $^{238}\mathrm{U}$ and separated using the IGISOL mass separator coupled to a Penning trap, were used to perform $\ensuremath{\beta}$- and $\ensuremath{\gamma}$-coincidence spectroscopy of $^{107}\mathrm{Mo}$. Gamma transitions and excited levels in $^{107}\mathrm{Mo}$ were observed in $\ensuremath{\beta}$ decay for the first time. Spin and parity $1/{2}^{+}$ for the ground state of $^{107}\mathrm{Mo}$ is proposed, to replace the previous $5/{2}^{+}$ assignment. The experimental $\ensuremath{\beta}$-decay half-life of $^{107}\mathrm{Nb}$ was estimated to be $0.27\ifmmode\pm\else\textpm\fi{}0.02$ s.
β decay of Cd127 and excited states in In127
2019
A dedicated spectroscopic study of the β decay of 127Cd was conducted at the IGISOL facility at the University of Jyvaskyla. Following high-resolution mass separation in a Penning trap, β-γ-γ coincidences were used to considerably extend the decay scheme of 127In. The β-decaying 3/2+ and 11/2- states in 127Cd have been identified with the 127Cd ground state and the 283-keV isomer. Their respective half-lives have been measured to 0.45(+12-8)s and 0.36(4) s. The experimentally observed β feeding to excited states of 127In and the decay scheme of 127In are discussed in conjunction with large-scale shell-model calculations.
Beta decay of neutron-rich Co: Probing single-particle states at and above the N=40 subshell closure
1999
Neutron-rich Co nuclei with A=66–70 were produced by the laser-ionization isotope-separation on-line method. The β decay from these nuclei has been studied. A case example is given by reporting on the observed decay scheme of 68Co. The half life of the ground-state decay of this nucleus was measured to be 0.21(3) seconds. In addition, a new β decaying isomer half life of 1.16(25) seconds was discovered. The level scheme of 68Ni has been significantly extended, and an interpretation of the observed levels is made by assuming that the N=40 gap has the characteristics of a shell closure.
Beta decay of the new isotope101Sn
1995
The very neutron-deficient isotope 101Sn was produced in a 50Cr(58Ni, 2p5n) reaction and its decay properties were determined for the first time. By using chemically selective ion sources of an on-line mass separator, the energy spectrum and the half-life (3 ± 1 s) of beta-delayed protons of 101Sn were measured. These results are compared to theoretical predictions.